--- title: How do you take a picture of a black hole? | daily.dev description: Capturing the first picture of a black hole required turning Earth itself into a telescope, astrophysicist Shep Doeleman explains in this podcast interview.... canonical: https://daily.dev/posts/how-do-you-take-a-picture-of-a-black-hole--yo6ee7pvo twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: How do you take a picture of a black hole? | daily.dev og:description: Capturing the first picture of a black hole required turning Earth itself into a telescope, astrophysicist Shep Doeleman explains in this podcast interview.... og:url: https://daily.dev/posts/how-do-you-take-a-picture-of-a-black-hole--yo6ee7pvo og:image: https://api.daily.dev/og/posts/YO6Ee7pvo.png og:image:alt: How do you take a picture of a black hole? og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # How do you take a picture of a black hole? **[Hacker News](https://daily.dev/sources/hn)** · 52 min read · 0 upvotes · 0 comments ## Summary Capturing the first picture of a black hole required turning Earth itself into a telescope, astrophysicist Shep Doeleman explains in this podcast interview. His Event Horizon Telescope linked radio dishes worldwide using atomic clocks accurate to one second per 10 million years, letting 250 researchers combine signals as if from one Earth-sized instrument. The project produced the first images of M87* (6 billion solar masses, 55 million light-years away) and Sagittarius A* (4 million solar masses, 27,000 light-years away). Doeleman says adding telescopes in Chile, Mexico, Wyoming, the Canary Islands and potentially Tanzania could let the team produce actual movies of a black hole's event horizon by the early 2030s. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How was the Event Horizon Telescope able to take a picture of a black hole? It linked radio telescopes across the globe using very long baseline interferometry, effectively turning Earth into one giant telescope. Each site recorded radio waves tagged with ultra-precise hydrogen maser atomic clocks, accurate to about one second every 10 million years, so signals from different continents could be combined coherently and compared as if captured by a single dish. _Developers curious about large-scale distributed instrumentation can track deep dives like this one on daily.dev._ ### How big and far away is the M87 black hole compared to Sagittarius A*? M87's black hole is about 6 billion solar masses and sits roughly 55 million light-years away, while Sagittarius A* at the Milky Way's center is about 4 million solar masses and 27,000 light-years away. Because M87 is about 2,000 times farther but also about 2,000 times more massive, both appear roughly the same angular size in the sky, around 50 microarcseconds. _Anyone comparing astronomical scales and measurement techniques can follow more explainers like this on daily.dev._ ### Why did the Event Horizon Telescope image M87's black hole before Sagittarius A*, even though Sagittarius A* was the preferred target? Sagittarius A* is only 4 million solar masses, so matter orbits it in about half an hour, making its appearance change noticeably within a single night of observing and complicating imaging. M87's black hole, at 6 billion solar masses, has orbital timescales that make it essentially stationary during a night, so it was far easier to image first despite being much farther away. _Readers following how researchers overcome data and timing constraints can find similar science stories on daily.dev._ ## Community take How the wider developer community reacted, aggregated from 1 discussion and 71 comments across hackernews (as of 2026-10-31). **TL;DR:** Most of the discussion veers away from the podcast itself into deep physics tangents about black hole density, singularities, and cosmology, while a smaller but notable thread questions whether the EHT images are trustworthy or essentially algorithmic reconstructions rather than real photos. **Sentiment:** 20% positive · 55% mixed · 25% skeptical **The case for** - Several commenters praised the EHT project's analogies (like reading a coin's date from across the country) for making the achievement's scale understandable. - Some defended the imaging methodology, noting it has been validated against known objects and reflects broad scientific consensus that the targets are black holes. **The pushback** - Some questioned whether the published 'image' is a genuine photo or largely a machine-learning/algorithmic reconstruction prone to confirmation bias. - A few pointed to a paper and video arguing the Sagittarius A* image reconstruction may be flawed or a hallucination. - Some felt the article/podcast itself was thin on visuals and concrete explanation, wishing for an actual picture with annotated detail instead of just transcript text. **By community** - hackernews (mixed): The thread splits between long technical digressions on black hole physics/cosmology and a smaller skeptical strand questioning the legitimacy of the EHT imaging process. **Hottest debate:** Whether the EHT's black hole 'image' is a legitimate observation or essentially an algorithmically generated reconstruction shaped by prior assumptions. **Open questions** - How accurate is the EHT imaging algorithm, and how much of the final image reflects real data versus model assumptions? - Does the Vaiyda/Schwarzschild/Kerr theoretical framework actually match what's observed in real accreting black holes? **Highlights** > They got an image of something, yeah. Or, did they? "So we had been perfecting these imaging algorithms on synthetic data. We’d fed these algorithms made-up data. So we would take a black hole image that we might be looking at. We’d corrupt it with noise, and we’d send it through these algorithms, and we’d refine these to the point where we were pretty confident in these algorithms." Algorithms? For what? So they're not just taking a photo of something observed through a telescope. They're not really explaining this either. I'm trying to keep an open mind but I'm still not buying the whole black hole thing. There needs to be something more intellectually compelling than "we know it's a black hole because we know it's a black hole". Yes, you read that right. I am doubting this religion. "That was a moment where there was a lot of crying and screaming." another odd quote from this article, provided one is assuming this is supposed to be around the scientific method. > — [jon128 on hackernews · 1 comments](https://news.ycombinator.com/item?id=50303676) > It's not taking a photo. It's computation, based on a lot of real data, with a lot of inference and synthetic data. The idea is that it's broadly accurate but cannot capture fine detail. The approach has been calibrated against known objects like NRAO 530, a quasar near Sgr A* that has some known properties, and it's been used on both Sgr A* and M87. And the team has admitted there's a lot of uncertainty about exactly how accurate it is. Here [1] is a pretty good article about how it works. There's overwhelming scientific consensus that Sgr A* and M87* are black holes. It's not really provable at this point, but I don't think anyone doubts it. [1] https://www.discovermagazine.com/the-event-horizon-telescope... > — [atombender on hackernews](https://news.ycombinator.com/item?id=50308763) > there's a serious group of astrophysicists that actually disagree the photo was assembled properly at all long paper made short I think their carefully demonstrated argument is it's a machine-learning hallucination to see what we want Dr. Becky has excellent coverage of it, will link it in a moment when I find it here it is, well worth watching: * https://www.youtube.com/watch?v=9U6bvR6SzMo Miyoshi, Kito & Makino (2024; claim the Sag A* image is wrong) * https://academic.oup.com/mnras/article/534/4/3237/7660988 > — [ck2 on hackernews](https://news.ycombinator.com/item?id=50309337) > The EHT is a remarkable achievement in datagathering and collaboration. But I always sort of wonder, a bit of doubt if you will. seeing as the process(simplified nearly to the point of absurdity) is that of building a image generator based off what we think a black hole looks like then feeding it very vague spectral data and getting it to generate an image. isn't that a huge confirmation bias. That is. of course the black hole looks like simulated ones, that is how the generator was programmed to make them. > — [somat on hackernews · 1 comments](https://news.ycombinator.com/item?id=50302746) > What is “pure” energy? > — [nkrisc on hackernews · 2 comments](https://news.ycombinator.com/item?id=50303025) **Source threads** - [hackernews](https://news.ycombinator.com/item?id=50301717) · 90 points · 71 comments ## Similar posts on daily.dev - [Next-generation black hole imaging may help us understand gravity better](https://daily.dev/posts/next-generation-black-hole-imaging-may-help-us-understand-gravity-better-pst7qhzcw) · Ars Technica · 0 upvotes · 0 comments - [Sloan Digital Sky Survey Releases New Map Of Supermassive Black Holes](https://daily.dev/posts/sloan-digital-sky-survey-releases-new-map-of-supermassive-black-holes-inpkj1vck) · Hackaday · 0 upvotes · 0 comments - [Astronomers discover a brand-new type of astrophysical object: A black hole star](https://daily.dev/posts/astronomers-discover-a-brand-new-type-of-astrophysical-object-a-black-hole-star-6rgfil5ym) · MIT News · 0 upvotes · 0 comments - [Nasa launches telescope that will map two billion galaxies](https://daily.dev/posts/nasa-launches-telescope-that-will-map-two-billion-galaxies-nb02mkmoc) · TechCentral · 1 upvotes · 1 comments --- Tags: [#astrophysics](https://daily.dev/tags/astrophysics) [View this post on daily.dev](https://daily.dev/posts/how-do-you-take-a-picture-of-a-black-hole--yo6ee7pvo) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"How do you take a picture of a black hole?","url":"https://daily.dev/posts/how-do-you-take-a-picture-of-a-black-hole--yo6ee7pvo","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/how-do-you-take-a-picture-of-a-black-hole--yo6ee7pvo"},"datePublished":"2026-10-30T18:36:11.928Z","dateModified":"2026-10-31T03:37:05.327Z","description":"Capturing the first picture of a black hole required turning Earth itself into a telescope, astrophysicist Shep Doeleman explains in this podcast interview....","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/3031e1e17f5407c205758318eccc5a57?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/3031e1e17f5407c205758318eccc5a57?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hacker News","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hacker News","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/hn","url":"https://daily.dev/sources/hn"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/how-do-you-take-a-picture-of-a-black-hole--yo6ee7pvo","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"astrophysics","timeRequired":"PT52M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hacker News","item":"https://daily.dev/sources/hn"},{"@type":"ListItem","position":3,"name":"How do you take a picture of a black hole?"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/how-do-you-take-a-picture-of-a-black-hole--yo6ee7pvo#faq","mainEntity":[{"@type":"Question","name":"How was the Event Horizon Telescope able to take a picture of a black hole?","acceptedAnswer":{"@type":"Answer","text":"It linked radio telescopes across the globe using very long baseline interferometry, effectively turning Earth into one giant telescope. 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